Using a clay block for car washing is similar to using a traditional clay bar but can be more efficient for larger surfaces. Here's how you can use a clay block effectively:

1. Prepare Your Vehicle: Wash and rinse your car thoroughly to remove loose dirt and debris. The surface should be clean before using the clay block.

2. Lubricate the Surface: Spray a generous amount of clay lubricant or soapy water onto a small section of the car's surface where you'll start working. This lubrication helps the clay block glide smoothly over the paint and prevents it from sticking.

3. Prepare the Clay Block: Knead the clay block in your hands to soften it slightly. This makes it more pliable and easier to work with.

4. Use Light Pressure: Glide the clay block over the lubricated surface using light to moderate pressure. Move the clay block back and forth in straight lines or in a cross-hatch pattern. Ensure you cover the entire section evenly.

5. Check for Smoothness: As you work, you'll feel the clay block grabbing contaminants. Continue until the surface feels smooth and there's no more roughness under the clay.

6. Fold and Re-knead: Periodically fold the clay block to expose a clean surface. This prevents trapped contaminants from scratching the paint. If the clay block becomes too dirty or drops onto the ground, discard that portion and use a fresh piece.

7. Rinse and Dry: After claying each section, rinse off any residue with clean water. Dry the surface with a microfiber towel.

8. Inspect and Repeat: Inspect the surface to ensure it's smooth and free of contaminants. If needed, repeat the process on other sections of the car.

9. Finish: After claying, you can proceed with polishing, waxing, or applying a sealant to protect the paint.

10. Clean and Store: Rinse the clay block with clean water after use to remove any remaining residue. Store it in a clean, sealed container to keep it pliable and ready for future use.

Using a clay block effectively requires patience and attention to detail. It's a methodical process that helps restore the smoothness of your car's paint by removing embedded contaminants. Always follow the manufacturer's instructions for the specific clay block you're using to achieve the best results.